Discharge electrode apparatus for electrostatic precipitators



Sept. 25, 1962 D. J. GONZALEZ DISCHARGE ELECTRODE APPARATUS FOR ELECTROSTATIC PRECIPITATORS 2 Sheets-Sheet 1 Filed March 11, 1960 INVENTOR. DON J. GONZALEZ ATTORNEY p 25, 1962 D. J. GONZALEZ 3,055,159

DISCHARGE ELECTRODE APPARATUS FOR ELECTROSTATIC PRECIPITATORS Filed March 11, 1960 2 Sheets-Sheet 2 II I \l i 3/6. 5 37 L36 min WI 33 33 38 3e: 3a 33 t(?%L 1 o 1* !L 0 {LL #3: F] L V \J L I l L I I a I r} I l I 0 4| Ilfii 42 K 39 39 42 J/G. 7 INVENTOR.

DON J. GONZALEZ 62,91. Q. QM

ATTORNEY United rates Fatent Q a 3,055,159 DISCHARGE ELECTRODE APPARATUS FOR ELECTROSTATIC PRECIPITATORS Don J. Gonzalez, Valley Station, Ky., assignor to American Air Filter Company, Inc., Louisville, Ky., a corporation of Delaware Filed Mar. 11, 1960, Ser. No. 14,245 3 Claims. (Cl. 55147) The present invention relates to electrostatic precipitators and more particularly to an improved discharge electrode apparatus for electrostatic precipitators.

It has been frequently necessary in the art of gas cleaning by electrostatic precipitation to interrupt the operation of an electrostatic precipitator in order to repair or remove a broken electrode discharge Wire in the precipitator, the broken wire creating hazardous and undesirable arc-overs. Such operational interruption is not only in itself costly but, in addition, the required repair or removal of the broken wire frequently presents a further problem, since the broken portion of the wire is often difficult to get to for such repair or removal.

The present invention, recognizing the disadvantages of past operations, avoids the same by providing an apparatus which, in the event of breakage in one of the discharge electrode Wires, automatically removes such wire from the path of the fluid stream being treated so that gas cleaning operations can continue without costly operattional interruptions.

Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth hereinafter.

More particularly, the present invention provides a discharge electrode apparatus for an electrostatic precipitator comprising elongated discharge electrode means, support means to support said electrode means across the fluid stream to be treated by the precipitator, and means cooperating with the discharge electrode means to insure automatic removal thereof from the fluid stream in the event of breakage of such electrode means.

It is to be understood that various changes can be made in the arrangement, form and construction of the apparatus disclosed herein without departing from the scope or spirit of the present invention.

FIGURE 1A is a schematic plan view of an electrostatic precipitator which incorporates the improved discharge electrode apparatus of the present invention;

FIGURE 1B is a schematic elevational view of the precipitator of FIGURE 1A;

FIGURE 2 is an enlarged, exploded perspective view of a retracting mechanism for the discharge electrode wires;

FIGURE 3 is a side elevational view of the retracting mechanism of FIGURE 2 in assembled form but with the cover partially broken away;

FIGURE 4 is a cross-sectional view of the retracting mechanism of FIGURE 3 taken in a plane passing through line 44 of FIGURE 3.

FIGURE 5 is a view of a portion of a discharge electrode wire which incorporates a quick disconnect apparatus intermediate its extremities;

FIGURE 6 is a schematic elevational view of a modification of the present invention wherein weights are used as electrode retracting means; and,

FIGURE 7 is a schematic view of still a further modification of the present invention which incorporates weights as electrode retracting means.

Referring to FIGURE 1 of the drawings, a portion of an electrostatic precipitator is disclosed. The precipitator, as is well known in the art, includes an ionizer zone 2 and a collector zone 3. Collector zone 3 is comprised of plate sets 4 and 6, the plates of the sets being interleaved Patented Sept. 25, 1962 in spaced relation with the plates of one set having a different electric potential than the plates of the other set so as to provide a voltage gradient therebetween. As is known in the art, selected plates of one of the sets-- set 4 in the embodiment shown-are arranged to extend into the ionizer zone 2 to cooperate with the spaced, parallel discharge electrode wires 7.

To support discharge electrode wires 7 in proper position in the fluid stream to be treated, a pair of spaced upper and lower bus bar members 9 is provided, these bus bar members being connected to a suitable source of electric power (not shown). Each of bus bar members 9 has mounted thereon a set of spaced right angle bracket members 11, one. leg of each bracket member being fastened to the bus bar and the other leg being free to support a retracting member 12. It is to be noted that spaced bracket members 11 of one set on one bus bar are in vertical alignment with corresponding spaced bracket members of a set on the other bus bar.

As can be more clearly seen in FIGURE 2 of the drawings, each retracting member 12 includes a cylindrically shaped housing 13 having a side wall 14. Fixed to the side wall 14 of the housing to extend along the central axis of the housing is a hollow sleeve member 16. Sleeve member 16, in turn, engages in fast telescopic relationship with a post 18 extending from the free end of bracket member 11 to which it is fastened. Disposed within the housing to surround sleeve 16 is a coil spring 22. As will be noted in FIGURE 3, the inner end of coil spring 22 is fastened to sleeve 16. It is to be understood that, if desired, coil spring 22 can be of the constant tension type so that a constant tension will be maintained on the discharge electrode 7 which is connected to the retracting member in a manner described hereinafter.

Fastened to the free end of coil spring 22 in rotatable fashion relative sleeve 16 is cylindrical cap 23. Cap 23 encloses spring 22 to shield it from any dust or moisture which might pass into housing 13 and otherwise create rusting and undesirable binding of the spring. The cap 23 is provided with spaced tabs 24 on the side wall 26 thereof, these tabs serving to engage in slots 26 which are provided in a wall of a sheave 27 so as to hold such sheave in fixed relationship to the cap. The sheave 27, to which a discharge electrode 7 is fastened, has a centrally disposed aperture to permit the sheave to rotate about and relative a hollow bushing 28 which engages post 18. It is to be noted that bushing 28 has an internally disposed spline 29 adapted to matingly engage in the slotted extremity 30 of post 18 so as to maintain the bushing in position. To enclose the above described assembly in cylindrical housing 13, a snap cover member 3-1 is provided for the housing. It is further to be noted that the peripheral wall of housing 13 is provided with a slot 33 through which discharge electrode 7, connected to sheave 27, can extend.

The discharge electrode 7 with a portion thereof connected to and wound about sheave 27 passes through slot 33 and across the fluid stream passage of the precipitator to be attached to a similar retracting member 12 at the lower portion of the precipitator, the springs 22 of the retracting members serving to maintain the electrode under a preselected tension during operation. In the event of breakage of the electrode in the course of operation, springs 22 cause shaves 27 to rotate and the freely dangling portions of the discharge electrodes attached to the sheaves are retracted from the fluid stream. Thus, the past problems of arcing-over caused by such freely dangling portions are eliminated and it is not longer necessary to stop precipitating operations.

Referring to FIGURE 5 of the drawings, it is to be noted that, if desired, discharge electrode wires 7 can be provided intermediate the retracting members 12 with a quick disconnect arrangement similar to that shown in this figure. This quick disconnect can consist simply of a pair of books 32 which can be readily and easily engaged and disengaged from each other. With the use of such hooks 32 it is possible to remove the discharge electrode quickly and efiiciently for ready access to the electrode plates during cleaning operations. It is to be understood that the present invention is not limited to the particular quick disconnect coupling as disclosed in FIGURE 5 and, if desired, other quick disconnect arrangements Le, a swivel mounted ball and socket arrangement, can also be used in place of the arrangement disclosed.

Referring to FIGURES 6 and 7, a further modification of the present invention is schematically disclosed wherein Weight members are substituted for the spring-type electrode retracting mechanism set forth in FIGURES 1-4. In FIGURE 6, a weight member 33 is connected to each extremity of discharge electrode 34. The electrode is then suspended intermediate the Weights on a pair of spaced idler sheaves 35 which are supported at the top of the precipitator housing so that the electrode 34 provides a double pass arrangement across the face of the precipitator with the electrode being held in proper tension by weights 33. A horizontal stop bar 36 is fastened to the lower portion of the precipitator housing. The stop bar is provided with apertures 37 which are smaller than the diameter of the weights but which permit the electrodes 32 to pass therethrough, thus preventing undesirable see-sawing of the electrode. In the event the electrode should break during the course of operation, the Weights 33 fall by gravity to withdraw the portions of the electrode attached thereto out of the fluid stream passage. It will be obvious that in this arrangement, as in FIGURE 7 described hereinafter, a precipitator housing of suitable depth can be provided to permit the Weights to pull the electrode portions clear of the electrode plate assembly. If desired, the housing can be shallow and, in the event of breakage, operations can he stopped momentarily to permit the broken portions to be withdrawn readily by merely pulling on the weights which fall to the housing floor.

In FIGURE 7, which discloses a structure that operates on a principle similar to that of the structure of FIGURE 6, spaced idler sheave pairs 38 and 39 are supported at the upper and lower portions of a precipitator housing, re spectively. A discharge electrode 41, having weights 42 attached to its extremities is supported intermediate such extremities on the idler sheave pairs in snake-like fashion, the back and forth passage of the discharge electrode wire 41 about the sheave pairs providing a plurality of electrode passes across the passage of the fluid stream to be treated. As in FIGURE 6, in the event of electrode breakage, the weights fall to the floor of the precipitator housing where they can be readily removed along with the broken portions attached thereto.

The invention claimed is:

-1. A discharge electrode apparatus for an electrostatic precipitator comprising an elongated discharge electrode wire, and a pair of spaced support means connected to opposite ends of said electrode wire to support said wire across a fluid stream to be treated by said precipitator, each of said support means including a rotatably mounted sheave disposed within a housing removed from the fluid stream, said sheave having an end of the electrode wire attached thereto and a spring member attached to said sheave to place said discharge electrode wire under tension in the fluid stream during normal operation and cause said wire to be automatically removed from the fluid stream so as to be wound about said sheaves within said housings in the event of breakage of said wire.

2. The apparatus of claim 1, said electrode means having a quick-disconnect means interposed between the ex tremities thereof.

3. A discharge electrode apparatus for an electrostatic precipitator comprising elongated discharge electrode means, and support means connected to said electrode means to support said electrode means across a fluid stream to be treated by said precipitator, said support means including a pair of spring loaded rotatable sheave retracting members, each disposed within one of a pair of spaced housings removed from the fluid stream, said retracting members cooperating with the extremities of said discharge electrode means to maintain said electrode means under tension during precipitating operations and to insure automatic removal and winding up of the severed portion of said electrode means within said housings in the event of breakage of said electrode means.

References Cited in the file of this patent UNITED STATES PATENTS 256,513 Sweet Apr. 18, 1882 FOREIGN PATENTS 174,995 Great Britain Feb. 15, 1922 462,637 Great Britain Mar. 12, 1937 676,495 Great Britain July 30, 1952 

